On an accurate α model for coarse mesh turbulent channel flow simulation

We present an analytical and numerical study of the reduced NS-α (rNS-α) model of incompressible fluid flow, which was recently proposed as an approximation to NS-α that allows for more efficient computations in the C0 finite element setting. Our analytical study consists of establishing connections between rNS-α to some well-studied models, and determining the model's integral invariants, energy cascade, and energy dissipation rate. Numerical simulations of turbulent flows with coarse meshes are performed, and excellent results found, for forced homogeneous, isotropic turbulence, and for turbulent channel flow with friction Reynolds numbers Reτ = 395, 590, and 1000.